As technology advances and increased automation and autonomy in aviation become ever more within reach, it makes sense to turn our attention to the operational regulatory landscape within which these aircraft will be flown. Technical standards that could be part of the means of compliance for the airworthiness certification of these aircraft are receiving attention within a variety of standards development organizations (SDOs). The operational rules and their implications for autonomous aircraft, however, remain largely unexplored.
This effort is an in-depth exploration into one such operational rule, U.S.C. Title 14 Code of Federal Regulations Part 91—General Operating and Flight Rules (Amdt 91-349). As stated in 14 CFR §91.1, Part 91 rules govern the operation of aircraft within the United States National Airspace System *. Interpreting the Part 91 regulations required a clear understanding of the semantics, hence it was essential to include 14 CFR §1.1- General Definitions in the formal analysis as well.
Intended for use by technical experts among SDOs, regulators, industry stakeholders, and academia, this report explains the process by which 14 CFR Part 91 (“Part 91”) was analyzed—which sections therein were determined to be potential large barriers to the widespread adoption of routine distributed highly automated and autonomous aviation operations—and offers some possible suggestions for addressing these barriers. The authors do not purport to have the regulatory solutions necessary to solve these problems: the intention is to identify potentially problematic areas of the existing regulatory landscape in a manner that, along with the current exemption and waiver process, can inform future data collection, technology development, and rulemaking efforts towards integration into the national airspace system (NAS).*
Motivating factors and potential follow-up activities from this work include informing future standards activities, informing potential future policy statements, inspiring a conversation about potential rulemaking activities, and providing a common frame of reference from which future potential regulatory relief may be requested. This work builds on, and is seen as a natural progression from, the previous Technical Reports, “Autonomy Design and Operations in Aviation: Terminology and Requirements Framework” and “Developmental Pillars of Increased Autonomy for Aircraft Systems
Sponsored and prepared by ASTM Technical Committees F37 on Light Sport Aircraft, F38 on Unmanned Aircraft Systems, F39 on Aircraft Systems, F44 on General Aviation Aircraft, and F46 on Aerospace Personnel.
*This Part does not apply to any aircraft or vehicle governed by Part 103—- Ultralight Vehicles or Sub-Part B, C, and D of Part 101—- Moored Balloons, Kites, Amateur Rockets, and Unmanned Free Balloons. Furthermore, except as provided in §§107.13, 107.27, 107.47, 107.57, and 107.59, Part 91 does not apply to any aircraft governed by Part 107—-Small Unmanned Aircraft Systems.